Vacuum pump



FIG. 1 is a front elevational view of a vacuum pump showing my new design;

FIG. 2 is rear elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a front right side perspective view thereof.

The broken lines in FIGS. 1 and 6 are included for the purpose of illustrating portions of the vacuum pump that form no part of the claimed design. 

CLAIM The ornamental design for a vacuum pump, as shown and described. 